Temporal and spatial segregation of activity favours the coexistence of morphologically similar species in neotropical carnivore assemblages

DI BITETTI, MARIO; PAVIOLO, AGUSTÍN; DE ANGELO, CARLOS; DI BLANCO, YAMIL; JIMÉNEZ PEREZ, IGNACIO; PEREIRA, JAVIER

Mendoza, Argentina

Congreso; 10th International Congress of Mammalogy; 2009

CCT CONICET Mendoza (CRICYT), CONICET, IADIZA, GiB, International Federation of Mammalogists, SAREM

Carnivores have been used as models to understand the effects of competition in community structure. Community-wide character displacement has been described in carnivore assemblages and interpreted in the light of the competitive exclusion principle. However, some sympatric Neotropical cats and foxes are morphologically similar and share similar diets (e.g., jaguarundimargay- oncilla, pampas fox and crab-eating fox). Behavioral mechanisms that facilitate species coexistence are still poorly explored and may explain these supposed exceptions to the competitive exclusion principle. Using the results of camera-trap surveys conducted in the Atlantic Forest (AF) and the Iberá Reserve (IR) of NE Argentina between 2003 and 2009 we describe the spatial and temporal patterns of records of syntopic cat and fox species to elucidate behavioral differences that may facilitate species coexistence. In the AF, the morphologically more similar cat species had the most contrasting spatial and temporal patterns of records: the margay was exclusively nocturnal and the jaguarundi diurnal and they showed a negative spatial association. Felid species alternate their peaks of activity in an orderly pattern in relation to their body weights. At IR, the crab-eating fox was more frequently recorded in forest habitats than the pampas fox, which preferred the grasslands, but their recording rates were not negatively correlated. The pampas fox showed mostly diurnal activity in areas where the nocturnal crab-eating fox was more abundant. The contrasting temporal patterns observed between the morphologically more similar pairs of species and the ability of some species to adjust their activity patterns to local conditions may facilitate the coexistence of these carnivore species. This may also explain the lack of a community-wide character displacement in the Neotropical felid assemblage. Time partitioning is an important mechanism that allows the coexistence of carnivore species.